As part of Cisco's ongoing commitment to proactive security and product quality, engineering teams for Cisco Emergency Responder, Cisco Prime Collaboration Deployment, Cisco Unified Communications Manager (Unified CM), Cisco Unified Communications Manager IM & Presence Service (Unified CM IM&P), Cisco Unified Communications Manager Session Management Edition (Unified CM SME), and Cisco Unity Connection have conducted a comprehensive internal security review. This review resulted in software hardening releases that address multiple internally discovered vulnerabilities.
The vulnerabilities tracked by CVE-2026-76473 are related to issues concerning improper control of a resource through its lifetime that are grouped under the Common Weakness Enumeration (CWE) Class CWE-74.
A vulnerability in Cisco Expressway Series could allow an unauthenticated, remote attacker to obtain sensitive information from an affected device.
This vulnerability is due to insufficient authorization checks of HTTP requests during Mobile and Remote Access (MRA) provisioning. An attacker could exploit this vulnerability by submitting a crafted URL request to an affected device. A successful exploit could allow the attacker to access sensitive information that they would otherwise not have authorization to access.
Note: Cisco Expressway Series refers to Cisco Expressway Core (Expressway-C) devices and Cisco Expressway Edge (Expressway-E) devices.
A vulnerability in the database service feature of Cisco Expressway Series could allow an unauthenticated, remote attacker with network access to a Cisco Expressway device to execute arbitrary operating system commands as root.
This vulnerability is due to the use of persistent cookies. Additionally, there is insufficient validation of client certificates when the TLS Verify Mode is set to Enabled for clustering, which means that client certificates are not validated. An attacker with possession of the cookies could exploit this vulnerability by connecting to the database service and invoking specific remote procedure call (RPC) commands. A successful exploit could allow the attacker to execute arbitrary commands as root on the underlying operating system of an affected device.
Note: Cisco Expressway Series refers to Cisco Expressway Core (Expressway-C) devices and Cisco Expressway Edge (Expressway-E) devices.
A vulnerability in the interprocess communication (IPC) channel of the Secure Firewall Posture module in Cisco Secure Client could allow an authenticated, local attacker to elevate privileges on an affected device.
This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by sending a series of crafted IPC messages to a local socket. A successful exploit could allow the attacker to perform limited file write operations on the filesystem with SYSTEM or root privileges.
Although this vulnerability affects the Secure Firewall Posture module in Cisco Secure Client on Windows, macOS, and Linux operating systems, this vulnerability could be used to obtain full root privileges on macOS and Linux. For that reason Cisco has assigned this security advisory a Security Impact Rating (SIR) of High rather than Medium as the score indicates.
CVE-2026-20356 is a high-severity vulnerability in Cisco Cyber Vision involving uncontrolled resource consumption. It was identified during an internal security review by Cisco's Snort 3 engineering team. The issue can lead to denial of service by exhausting system resources. Multiple specific versions of Cisco Cyber Vision are affected. No known exploits are reported in the wild. No patch or remediation details are provided in the input data.
CVE-2026-20236 is a high severity vulnerability in Cisco Cyber Vision involving incorrect calculation issues. These issues fall under the CWE-682 category and were identified during an internal security review by Cisco's Snort 3 Software engineering team. The vulnerability impacts multiple specific versions of Cisco Cyber Vision. The CVSS score of 7.5 indicates a high severity with network attack vector, low attack complexity, no privileges required, no user interaction, and an impact limited to availability. There are no known exploits in the wild and no vendor advisory or patch information is provided.
CVE-2026-20221 is a medium severity vulnerability in Cisco Cyber Vision affecting multiple versions. It involves a NULL pointer dereference in the Snort 3 Detection Engine's handling of nested GRE tunnel decapsulation. An unauthenticated remote attacker can send crafted GRE payloads to trigger an unexpected restart of the detection engine, causing denial of service or bypass conditions depending on configuration. The Snort 3 Detection Engine restarts automatically without manual intervention.
CVE-2026-20291 is a high-severity vulnerability in Cisco Cyber Vision involving improper privilege management. It affects multiple specific versions of the product. The flaw allows an attacker with limited privileges to potentially gain elevated access, impacting confidentiality, integrity, and availability. No known exploits are reported in the wild. Cisco has conducted internal security reviews and released software hardening updates addressing these issues.
CVE-2026-20197 is a medium severity vulnerability in Cisco Open Source Snort3 affecting multiple versions. It involves improper restriction of operations within the bounds of a memory buffer in the Snort 3 Teredo Detection Engine. An unauthenticated remote attacker can send crafted Teredo packets that cause the Snort 3 Detection Engine to restart unexpectedly, resulting in a denial of service (DoS) condition by interrupting packet inspection.
CVE-2026-20218 is a stack-based buffer overflow vulnerability in the Snort 3 Visual Basic for Applications (VBA) Decompression Engine used by multiple Cisco products. An unauthenticated remote attacker can exploit this flaw by sending specially crafted VBA data to the Snort 3 Detection Engine, causing it to restart unexpectedly and resulting in a denial of service (DoS). This vulnerability arises from improper range checking during VBA data decompression. The issue affects multiple specific versions of Cisco Open Source Snort3.
A vulnerability in Cisco Open Source Snort3's GRE Detection Engine allows unauthenticated remote attackers to cause the detection engine to restart by sending crafted GRE packets. This results in a denial-of-service (DoS) condition due to interruption of packet inspection.
CVE-2026-20043 is a critical vulnerability in Cisco Cyber Vision involving out-of-bounds write issues. These vulnerabilities were identified during an internal security review by Cisco's Snort 3 Software engineering team and relate to CWE-787. The flaw affects multiple specific versions of Cisco Cyber Vision. The CVSS v3.1 score is 9.0, indicating high impact on confidentiality, integrity, and availability. No public exploits are known, and no patch or remediation details are provided in the input data.
CVE-2026-20019 is a medium severity vulnerability in Cisco Open Source Snort3 affecting multiple versions. It involves an infinite loop caused by incomplete error checking when parsing UDP Netflow Protocol packets. An unauthenticated remote attacker can exploit this by sending a crafted Netflow packet, causing the Snort 3 Detection Engine to restart unexpectedly and resulting in a denial-of-service (DoS) condition.
CVE-2026-20011 is a medium severity vulnerability in Cisco Open Source Snort3 affecting multiple versions. It involves a buffer access issue with incorrect length values in the Snort 3 SMTP MIME Decoder. An unauthenticated remote attacker can exploit this by sending crafted SMTP packets, causing the Snort 3 Detection Engine to restart unexpectedly, resulting in a denial of service (DoS).
A vulnerability in the Advanced Malware Protection (AMP) feature of Cisco Secure Email Gateway could allow an unauthenticated, remote attacker to write arbitrary files on the underlying operating system.
This vulnerability is due to improper handling of email attachments when the file reputation service is enabled. An attacker could exploit this vulnerability by sending an email that contains a crafted attachment through an affected device. A successful exploit could allow the attacker to write arbitrary files and execute commands with root privileges on the underlying operating system.
This is an advance notification from Cisco about the scheduled publication of security advisories on October 21, 2026. It informs customers about the regular cadence of security vulnerability disclosures under Cisco's risk-based disclosure process, which typically occur on the first and third Wednesday of each month. The notice clarifies that the schedule is tentative and subject to change, with potential additions or removals of advisories depending on readiness. No specific vulnerabilities or threats are detailed in this notification.
CVE-2026-76472 is a high-severity vulnerability in Cisco Campus Gateway Software involving improper neutralization of special elements in output used by downstream components, categorized as an injection issue. It affects numerous specific versions of the software. The vulnerability has a CVSS score of 8.8, indicating high impact on confidentiality, integrity, and availability. No known exploits are reported in the wild, and no patch or remediation details are provided in the available data.
CVE-2026-76467 is a high-severity vulnerability in Cisco Campus Gateway Software involving improper control of a resource through its lifetime. The issue was identified during Cisco's internal security review and is classified under CWE-664. The vulnerability does not impact confidentiality or integrity but can cause a denial of service due to availability impact. It affects multiple specific versions of Cisco Campus Gateway Software. No known exploits are reported in the wild. No explicit patch or remediation details are provided in the input data.